Spline-finishing broach



F. I. LAPOINTE.

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FRANCIS J. LAPOINTE, OF ANN ARBOR, MICHIGAN.

SPLINE-FINISHING BROAGH.

Specification of Letters Patent.

Patented May 3, 1921.

Application fled January 27, 1920. Serial No. 356,050.

T 0 all whom it may concern:

Be it known that I, FnA'Nors J. LAPOINTE, a citizen of the United Statesof America, and a resident of Ann Arbor, in the county of Washtenaw andState of Michigan, have invented certain new and useful Improvements inSpline-Finishing Broaches, of which the following is a specification.

This invention relates to spline finishing broaching tools and has forits object the provision of means whereby, in a single operation, thecentral opening in the work being operated upon will be 'made concentricwith the outer ends of the splines cut therein.

The invention consists in providing a spline broaching tool with aremovable member at the outer end having a plurality of teeth thereonadapted to cut away the portions of the stock between the splinespreviously cut and thereby form a central bore or opening thecylindrical walls of which will be concentric to the outer ends. of saidsplines.

The invention further consists of certain novel features of constructionand arrangement of parts which will be understood readily by referenceto the description of the drawings and to the claims to be hereinaftergiven.

For the purpose of illustrating the mvention, one preferred form thereofis illustrated in the drawings, this form having been found to givesatisfactory and reliable results although it 'is to be understood thatthe various instrumentalities of which the invention consists can bevariously arranged and organized and the invention is not limited to theprecise arrangement and organization of these instrumentalities asherein shown and described except as required by the s'co of theappended claims.

Of t e drawings:

Figure 1 represents an elevation of a broaching tool embodying theprinciples of v the present invention.

Fig. 2 represents a longitudinal section of the finishing end of saidtool, drawn to an enlarged scale.

Fig. 3 represents a transverse sectlon on line 3, 3, on Fig. 1.

Fig. 4 represents a transverse section on line 4, 4, on Fig. 2.

Fig. 5 represents a transverse section on line 5, 5, on Fig. 1, and

Fig. 6 represents an elevation of the finishing end of said tool.

Similar characters indicate like parts throughout the several figures ofthe drawmgs.

In the drawings, 10 is a cylindrical portion of the broaching toolhaving a diametteeth of each set adjacent to the cylindrical portion 10extending slightly be 0nd the riphery of said cylindrical portion and'eziir h succeeding tooth in each row toward the outer end of thebroaching tool extending slightly beyond the preceding tooth.

As this portion of the broaching tool is drawn through a cylindricalepenlng in a piece of work, a plurality of splines will be cut into thework, said splines radiating from the axis of said cylindrical openingin said work.

The opening in the work has a diameter slightly greater than thediameter of the portion 10 of the broaching tool and as a consequence,owing to the play between the cylindrical wall of the opening in thework and the periphery of the'cylindrical portion 10, it is not alwayspossible to make the bottoms of the splines which are cut into the work,concentric with the axis of the openin through the work.

is is very objectionable particularly when it is deslred to cut gearteeth on the periphery of the work for obviously the pitch circle of theteeth, the bottoms of the splines and the cylindrical opening throughthe gear should all be concentric.

In order to accomplish this result, the broaching tool is provided witha cylindrical shank 15 between the outer end thereof and the flange 12.

This flange 12 is provided at its outer end with a cone-shaped recess 16and the outer end of said shank 15 is threaded at 17 to receive a nut 18having a similar cone-shaped recess 19 on its inner end.

In the periphery of the shank 15 near the outer end thereof, is alongitudinal slot 20 adapted to receive the inner end of a screw 21threaded to a sleeve 22 fitted over and surrounding the shank 15.

This sleeve 22 is provided preferably with as many longitudinal grooves23 as there are sets of alined teeth 14 in the tapered portion 13 of thebroaching tool although a smaller number may be used.

In each of the grooves 23 is disposed a bar 24, the width of which isthe same as the width of the splines cut by the teeth .14.

Between these bars 24, the sleeve 22 is provided with a series ofcutting teeth 25 each succeeding tooth toward the outer end of thebroaching tool being slightly greater in diameter than the toothpreceding it.

The diameter of the teeth 25 nearest the flange 12 is the same as thediameter of the spline-cutting tooth 14' adjacent to the cylindricalportion 10. a

The sleeve 22 at its outer end is provided with a cylindrical portion 26of the same diameter as the last cutting tooth 25 or a trifle less thansaid cutting tooth, this cylindrical portion 26 being adapted to removethe burrs from the opening andpolish the cylindrical wall thereof. Theopposite ends of the bars 24 are inclined as indicated at 27 with thelower ends thereof positioned within the recesses 16 and 19 of theflange 12 and nut 18 respectively.

The cutting edge of the outer teeth 25 is below the outer face of thebar 24 a distance equal to the required depth of spline.

When the breaching tool is in use, the

work is positioned upon the portion 10, the tool is then connected tothe tool holder on the carriage of the broaching machine and thebreaching tool is drawn through the work thereby cutting into the work apluralit of splines.

- A ter the cutting of the splines has been completed, the continuedmovement of the broaching tool, will cause the bars 24 to enter thesplines previously cut and the teeth 25 will be drawn throu h theopening in the work cutting away su cient material from the work tocause the finished o. ening to be concentric with the bottoms of t esplines.

The threaded member 21 in the longitudinal slot 20 retains the sleeve 22in position so that the bars 24 will always be in alinement with therows of spline-cutting teeth 14.

Th body portion of the broaching tool including the spline-cutting teeth14 will outlast several of the sleeves 22 and when one of these sleevesbecomes worn or broken, it may readily be removed from the shank 15 andreplaced by another sleeve.

In the same manner the bars 24 when worn, may be removed from the sleeve22 and replaced by new bars 24.

By the use of a tool of this description an annular piece of metal maybe placed upon the portion 10 and the required number of splines cuttherein and the central opening in said work then may be reamed out sothat its cylindrical wall will be concentric with the bottoms of thesplines thereby making it possible to place the same upon a gear machine and more accurately cut the gear teeth on the periphery of saidwork.

While only four sets of alined teeth 14 and bars 24 are shown, it isobvious that any number of sets of teeth and bars may be used withoutaffecting the invention.

It is believed that the operation and many advantages of the inventionwill be thoroughly understood without further descrliption.

aving thus described my invention, I claim- 1. A broaching tool providedwith a plurality of spline-cutting teeth and having a reduced shank atthe outer end thereof; and a non-revoluble member, surrounding saidshank, provided with ribs adapted to project into the splines cut intothe work and having cutting teeth between said ribs.

2. A broaching tool provided with a plu rality of spline-cutting teethand having a reduced shank at the outer end thereof; and a non-revolublemember, surrounding said shank, provided with removable ribs adapted toproject into the splines cut into the wgrk and having cutting teethbetween said r1 5.

3. A broaching tool provided with a plurality of splinecutting teeth andhaving a reduced shank at the outer end thereof; and a non-revolublemember, surrounding said shank, provided with ribs adapted to projectinto the splines cut into the work and having cutting teeth between saidribs of less depth than said ribs.

4. A broaching tool having a plurality of spline-cutting teeth andprovided at its outer end with means for cutting away portions of thematerial between the splines cut by said teeth.

5. A broaching tool having a plurality of spline-cutting teeth andprovided at its outer end with a plurality of sets of members forcutting away portions of the material between the splines cut by saidteeth.

6. A broaching tool having a plurality of spline-cutting teeth andprovided at its outer end with a cylindrical shank; a toothed sleevefitted onto said shank and having a plurality of peripheral groovesextending longitudinally thereof; ribs in said grooves and extendinginto said splines; and means for retaining said sleeve and ribs inposition.

7. A broaching tool having a plurality of spline-cutting teeth andprovided at its outer end with a recessed flange and a cylindricalshank; a toothed. sleeve fitted onto said shank and having a pluralityof peripheral grooves extending longitudinally thereof; ribs in saidgrooves extending into said splines and beyond the ends of said sleeves;and a recessed nut threaded to said shank for retaining said sleeve andribs in position with the ends of said ribs in the recesses of saidflange and nut.

8. A broaching tool provided with a plurality of spline-cutting teethand having a reduced shank at the outer end thereof; and a non-revolublemember on said shank provided with ribs adapted to extend into thesplines cut into the work, said member also having a plurality of setsof teeth between said ribs, each set of teeth nearest the outer endhaving a greater depth than those next adjacent thereto toward the innerend of said member.

9. A broaching tool provided with members for cutting a plurality ofsplines in a piece of work having a cylindrical opening therethrough andprovided with means at the outer end thereof for enlarging said opening.

10. A broaching tool provided with members for cutting a plurality ofsplines in a piece of work having a cylindrical opening therethrough andprovided with means at the outer end thereof for enlarging said openingand making its cylindrical Wall concentric to the bottoms of saidsplines.

Signed by me at 746-7 Old South Bldg, Boston, Mass, this 12th day ofJanuary,

FRANCIS J. LAPOINTE. Witnesses:

WALTER E. LOMBARD, NATHAN C. LOMBARD.

